Carrier route record
DLAUS→SEA
Delta Air Lines · Austin to Seattle
- Flights
- 949
- Period
- September 2025 to August 2026
- Share of route
- 45%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on AUS to SEA lands a B+, 7 points better than the national rate of 77.3%. About one flight in six arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That rests on 949 flights, with a median arrival 10 minutes early.
Set against the rest of the country, Delta's AUS to SEA record is 7 points better than the US average of 77.3%. That gap is worth roughly 65 fewer late arrivals for every thousand flights.
Key figures
On time
83.8%
Arrivals under 15 minutes late, of 938 completed flights
Avg delay
82 min
Across delayed arrivals only, not all flights
Cancelled
0.95%
National rate is 1.89%
Whole route
81.3%
Every carrier on AUS to SEA, 2,089 flights
These figures cover 949 flights between September 2025 and August 2026. The median arrival is 10 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
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Carrier by carrier
Delta against every carrier on AUS to SEA
Delta flew 949 of the 2,089 flights on AUS to SEA, about 45% of it. Its 83.8% on time is 3 points better than the route as a whole, which runs 81.3%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from Delta at 83.8% to Southwest at 48.9%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines (this page) | 949 | 83.8% | 82 min | 0.95% | B+ |
| Alaska Airlines | 1,051 | 81.8% | 50 min | 0.76% | B+ |
| Southwest Airlinesthin sample | 89 | 48.9% | 38 min | 1.12% | F |
Flight by flight
Delta flight numbers on AUS to SEA
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Departure window
When Delta runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 19 points, against half a point between the best and worst carrier.
- 5am–8am325 flights92.9%
- 8am–11am25 flights—
- 11am–2pm253 flights86.4%
- 2pm–5pm21 flights—
- 5pm–8pm325 flights73.8%
- 8pm–5am—
Scale runs 65% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 92.9% of the time, against 73.8% for the evening window. That is 19 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 325 flights scheduled in it.
Across the year
Delta on AUS to SEA through the year
December is the weak month at 70.7% on time, against 91.9% in April. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. July was the busiest month here, with 93 flights.
Across the week, Saturday is the strongest day at 89.5% on time and Thursday the weakest at 77.2%, a spread of 12 points.
Arrival by arrival
How late Delta on AUS to SEA runs when it is late
Delta on AUS to SEA often beats the schedule: 357 of 938 completed flights, 38%, arrived 15 minutes or more early. The 152 late arrivals split 53 under half an hour, 37 between 30 and 60 minutes, and 62 an hour or more.
- 15+ min early357 flights38.1%
- Within 15 min429 flights45.7%
- 15–29 min late53 flights5.7%
- 30–59 min late37 flights3.9%
- 1–2 hours late30 flights3.2%
- 2+ hours late32 flights3.4%
Scale runs 0% to 100%.
Share of 938 completed flights by arrival against schedule.
33 of 156 late departures made up the time and arrived on time, 21% of them. 29 flights left on time and still arrived late.
The worst days
Worst days for Delta on AUS to SEA
The latest arrival of the period was on 13 March 2026, 16 hours 21 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 13 March 2026 | 16 hours 21 minutes | Carrier |
| 27 May 2026 | 9 hours 34 minutes | Extreme weather |
| 1 September 2025 | 6 hours 59 minutes | Carrier |
| 22 July 2026 | 5 hours 7 minutes | Late-arriving aircraft |
| 17 April 2026 | 4 hours 40 minutes | Carrier |
Delay causes
Why Delta runs late on this route
Carrier accounts for 46% of the 13,000 delay minutes carriers reported here, and the remaining four split what is left.
- 46%Carrier
- 40%Late-arriving aircraft
- 9%National Airspace System
- 6%Extreme weather
40% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 13,000 reported delay minutes here, that single category outweighs weather by 7 to one. The split is drawn from 12,504 reported delay minutes.
The largest share of delay minutes, 46%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 5,703 of the 13,000 delay minutes reported here.
Cancellations sit at 0.95% against a national 1.89%, which is ordinary. Diversions add another 0.21%.
Connections and stage length
What a delay here costs
6.6% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last an hour and a half, which a normal layover absorbs.
At 1,770 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg is a different operation and performs like one: it runs 80.1% on time across 950 flights, 4 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 4 points of difference.
One caution: this is a thin sample. 949 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking Delta on AUS to SEA
Put together: treat all of this as provisional. 949 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 83.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 938 completed flights over 12 months sit behind that.
Related
Where to go next
- AUS to SEA, every carrier
- Delta on SEA to AUS, the return leg
- Alaska Airlines on AUS to SEA81.8%
- Delta Air Lines network-wide record
- Austin-Bergstrom International (AUS) delay statistics
- Seattle-Tacoma International (SEA) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.